1. Field of the Invention
The present invention relates to network switching devices and, more particularly, to high bandwidth switching devices.
2. Description of the Related Art
Today's communication markets continue to show strong growth as the bandwidth needed to satisfy the demands of the information age increases. In the carrier markets demand is being driven by the need for bandwidth-hungry data services alongside revenue-generating voice traffic. Digital Subscriber Line (DSL) technology may boost access bandwidth by one or two orders of magnitude while the core is benefiting from the provisioning of high numbers of DWDM (Dense Wavelength Division Multiplexing) circuits at higher bandwidths. Service providers are focusing their resources to create value-added intelligent edge services while the long haul and network core are seen as providing a low cost, high bandwidth interconnect. The metropolitan optical transport network with feeds from edge routers and switches must therefore support a broad variety of services and protocols.
Recent advances in switching have resulting in replacement of shared backplanes with switched backplanes because switched backplanes allow for the simultaneous transfer of multiple packets. See McKeown, “Fast Switched Backplane for a Gigabit Switched Router,” Cisco Systems, Inc., White Paper. These switched backplanes or switch fabrics are use for routing, switching and optical transport markets. Unfortunately, these recent advances still have performance (e.g., bandwidth) constraints. One particular constraint is that current architectures are not readily scalable to support higher bandwidths. Therefore, scalable, higher performance switch fabrics are needed to support routing, switching and optical transport markets.